• Adam Gundry's avatar
    Fix infix record field fixity (#11167 and #11173). · 6e56ac58
    Adam Gundry authored
    This extends D1585 with proper support for infix duplicate record
    fields.  In particular, it is now possible to declare record fields as
    infix in a module for which `DuplicateRecordFields` is enabled, fixity
    is looked up correctly and a readable (although unpleasant) error
    message is generated if multiple fields with different fixities are in
    scope.
    
    As a bonus, `DEPRECATED` and `WARNING` pragmas now work for
    duplicate record fields. The pragma applies to all fields with the
    given label.
    
    In addition, a couple of minor `DuplicateRecordFields` bugs, which were
    pinpointed by the `T11167_ambig` test case, are fixed by this patch:
    
      - Ambiguous infix fields can now be disambiguated by putting a type
        signature on the first argument
    
      - Polymorphic type constructor signatures (such as `ContT () IO a` in
        `T11167_ambig`) now work for disambiguation
    
    Parts of this patch are from D1585 authored by @KaneTW.
    
    Test Plan: New tests added.
    
    Reviewers: KaneTW, bgamari, austin
    
    Reviewed By: bgamari
    
    Subscribers: thomie, hvr
    
    Differential Revision: https://phabricator.haskell.org/D1600
    
    GHC Trac Issues: #11167, #11173
    6e56ac58
HsTypes.hs 45.2 KB